Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 188 insertions, 0 deletions

diff --git a/drivers/watchdog/arm_smc_wdt.c b/drivers/watchdog/arm_smc_wdt.c
new file mode 100644
index 000000000..8f3d0c3a0
--- /dev/null
+++ b/drivers/watchdog/arm_smc_wdt.c
@@ -0,0 +1,188 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ARM Secure Monitor Call watchdog driver
+ *
+ * Copyright 2020 Google LLC.
+ * Julius Werner <jwerner@chromium.org>
+ * Based on mtk_wdt.c
+ */
+
+#include <linux/arm-smccc.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+#include <linux/watchdog.h>
+#include <uapi/linux/psci.h>
+
+#define DRV_NAME		"arm_smc_wdt"
+#define DRV_VERSION		"1.0"
+
+enum smcwd_call {
+	SMCWD_INIT		= 0,
+	SMCWD_SET_TIMEOUT	= 1,
+	SMCWD_ENABLE		= 2,
+	SMCWD_PET		= 3,
+	SMCWD_GET_TIMELEFT	= 4,
+};
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+static unsigned int timeout;
+
+static int smcwd_call(struct watchdog_device *wdd, enum smcwd_call call,
+		      unsigned long arg, struct arm_smccc_res *res)
+{
+	struct arm_smccc_res local_res;
+
+	if (!res)
+		res = &local_res;
+
+	arm_smccc_smc((u32)(uintptr_t)watchdog_get_drvdata(wdd), call, arg, 0,
+		      0, 0, 0, 0, res);
+
+	if (res->a0 == PSCI_RET_NOT_SUPPORTED)
+		return -ENODEV;
+	if (res->a0 == PSCI_RET_INVALID_PARAMS)
+		return -EINVAL;
+	if (res->a0 != PSCI_RET_SUCCESS)
+		return -EIO;
+	return 0;
+}
+
+static int smcwd_ping(struct watchdog_device *wdd)
+{
+	return smcwd_call(wdd, SMCWD_PET, 0, NULL);
+}
+
+static unsigned int smcwd_get_timeleft(struct watchdog_device *wdd)
+{
+	struct arm_smccc_res res;
+
+	smcwd_call(wdd, SMCWD_GET_TIMELEFT, 0, &res);
+	if (res.a0)
+		return 0;
+	return res.a1;
+}
+
+static int smcwd_set_timeout(struct watchdog_device *wdd, unsigned int timeout)
+{
+	int res;
+
+	res = smcwd_call(wdd, SMCWD_SET_TIMEOUT, timeout, NULL);
+	if (!res)
+		wdd->timeout = timeout;
+	return res;
+}
+
+static int smcwd_stop(struct watchdog_device *wdd)
+{
+	return smcwd_call(wdd, SMCWD_ENABLE, 0, NULL);
+}
+
+static int smcwd_start(struct watchdog_device *wdd)
+{
+	return smcwd_call(wdd, SMCWD_ENABLE, 1, NULL);
+}
+
+static const struct watchdog_info smcwd_info = {
+	.identity	= DRV_NAME,
+	.options	= WDIOF_SETTIMEOUT |
+			  WDIOF_KEEPALIVEPING |
+			  WDIOF_MAGICCLOSE,
+};
+
+static const struct watchdog_ops smcwd_ops = {
+	.start		= smcwd_start,
+	.stop		= smcwd_stop,
+	.ping		= smcwd_ping,
+	.set_timeout	= smcwd_set_timeout,
+};
+
+static const struct watchdog_ops smcwd_timeleft_ops = {
+	.start		= smcwd_start,
+	.stop		= smcwd_stop,
+	.ping		= smcwd_ping,
+	.set_timeout	= smcwd_set_timeout,
+	.get_timeleft	= smcwd_get_timeleft,
+};
+
+static int smcwd_probe(struct platform_device *pdev)
+{
+	struct watchdog_device *wdd;
+	int err;
+	struct arm_smccc_res res;
+	u32 smc_func_id;
+
+	wdd = devm_kzalloc(&pdev->dev, sizeof(*wdd), GFP_KERNEL);
+	if (!wdd)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, wdd);
+
+	if (of_property_read_u32(pdev->dev.of_node, "arm,smc-id",
+				 &smc_func_id))
+		smc_func_id = 0x82003D06;
+	watchdog_set_drvdata(wdd, (void *)(uintptr_t)smc_func_id);
+
+	err = smcwd_call(wdd, SMCWD_INIT, 0, &res);
+	if (err < 0)
+		return err;
+
+	wdd->info = &smcwd_info;
+	/* get_timeleft is optional */
+	if (smcwd_call(wdd, SMCWD_GET_TIMELEFT, 0, NULL))
+		wdd->ops = &smcwd_ops;
+	else
+		wdd->ops = &smcwd_timeleft_ops;
+	wdd->timeout = res.a2;
+	wdd->max_timeout = res.a2;
+	wdd->min_timeout = res.a1;
+	wdd->parent = &pdev->dev;
+
+	watchdog_stop_on_reboot(wdd);
+	watchdog_stop_on_unregister(wdd);
+	watchdog_set_nowayout(wdd, nowayout);
+	watchdog_init_timeout(wdd, timeout, &pdev->dev);
+	err = smcwd_set_timeout(wdd, wdd->timeout);
+	if (err)
+		return err;
+
+	err = devm_watchdog_register_device(&pdev->dev, wdd);
+	if (err)
+		return err;
+
+	dev_info(&pdev->dev,
+		 "Watchdog registered (timeout=%d sec, nowayout=%d)\n",
+		 wdd->timeout, nowayout);
+
+	return 0;
+}
+
+static const struct of_device_id smcwd_dt_ids[] = {
+	{ .compatible = "arm,smc-wdt" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, smcwd_dt_ids);
+
+static struct platform_driver smcwd_driver = {
+	.probe		= smcwd_probe,
+	.driver		= {
+		.name		= DRV_NAME,
+		.of_match_table	= smcwd_dt_ids,
+	},
+};
+
+module_platform_driver(smcwd_driver);
+
+module_param(timeout, uint, 0);
+MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds");
+
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+			__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Julius Werner <jwerner@chromium.org>");
+MODULE_DESCRIPTION("ARM Secure Monitor Call Watchdog Driver");
+MODULE_VERSION(DRV_VERSION);